JPH08325437A - Etchant for cured epoxy resin - Google Patents

Abstract

PURPOSE: To enable the removal of an unmodified epoxy resin and attain good handleability by using an amide solvent and an aqueous solution of an alkali metal compound to form an etchant for a specific cured epoxy resin composition. CONSTITUTION: A bifunctional epoxy resin is mixed with a halogenated dihydric phenol in such a ratio that the amount of the phenolic hydroxyl groups is 0.9 to 1.1 equivalent based on the epoxy groups. This mixture is thermally polymerized at 60-150 deg.C in an amide or ketone solvent having a b.p. of 130 deg.C or higher at a reactant solid concentration of 50wt.% or lower in the presence of a catalyst to obtain a film-forming epoxy polymer (A) having a mol.wt. of 100,000 or higher. The ingredient (A) is compounded with a masked isocyanate and a polyfunctional epoxy resin as crosslinking agents, a curing agent, a curing accelerator, an amide solvent, and a 0.5-60wt.% aqueous solution of an alkali metal hydroxide. The amount of the isocyanate groups of the masked isocyanate is 0.1-1.0 equivalent based on the hydroxyl groups of the ingredient (A), and that of the polyfunctional epoxy resin is 20-100wt.% based on the ingredient (A).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an etching solution for a cured thermosetting epoxy resin, which can be used as a film and is used in insulating materials, adhesives, paints and the like.

[0002]

2. Description of the Related Art Epoxy resin is used in various fields because it has excellent electric characteristics and adhesiveness like polyimide resin. As the applications of epoxy resins and polyimide resins have expanded, some applications have been made such that a part of the resin is roughened or removed for use. Conventionally, etching of a polyimide resin has been often carried out, and a method of etching with a basic solution such as hydrazine is disclosed in Japanese Patent Laid-Open No. Sho 5-5.
0-4577, JP-A-51-27464,
And known from JP-A-53-49068.

Further, regarding roughening and etching of epoxy resin, concentrated sulfuric acid, chromic acid, and alkaline permanganate used for surface roughening treatment, desmear treatment, and etchback treatment of a cured epoxy resin used for a printed wiring board. A method of etching with salt or the like is disclosed in JP-A-54-1449.
No. 68 and Japanese Patent Laid-Open No. 62-104197. Further, a method of adding an alkali-soluble acrylic resin to an epoxy resin and performing etching is known from JP-A-5-218651.

[0004]

Concentrated sulfuric acid, chromic acid, and alkali permanganate are used for roughening and etching a cured product of an unmodified epoxy resin, but these solutions are labor intensive. It is a chemical that corresponds to a specified chemical substance under the Safety and Health Act, and requires sufficient precautions for safe handling, and the handler is obliged to carry out regular health checkups. Furthermore, since concentrated sulfuric acid has a strong water absorption property, it is necessary to control the concentration sufficiently, and in order to completely remove the epoxy resin with alkaline permanganate, a high temperature of around 80 ° C and a time of 30 minutes or more are required. there were. Further, in the case of a modified epoxy resin to which an acrylic resin is added to enable etching of the epoxy resin, excellent properties such as heat resistance and chemical resistance of the epoxy resin are deteriorated.

It is an object of the present invention to provide an etching solution which is easy to handle and is capable of removing an unmodified epoxy resin.

[0006]

The etching liquid for a cured epoxy resin of the present invention is a molecular weight having a film-forming ability obtained by heating and polymerizing a bifunctional epoxy resin and a halogenated bifunctional phenol in the presence of a catalyst. A solution for etching a cured product of a thermosetting epoxy resin composition comprising 100,000 or more epoxy polymer, a cross-linking agent, and a polyfunctional epoxy resin, the solution comprising an amide solvent and an aqueous solution of an alkali metal compound. Characterize.

As a result of intensive investigations, the present inventors have made various investigations on the decomposition reaction of high molecular weight epoxy polymers.
The present invention is based on the finding that a high molecular weight epoxy polymer is decomposed by an alkali metal compound in an amide solvent.

The present invention will be described in detail below. The cured product of the thermosetting epoxy resin composition, which is the object of etching of the present invention, is a molecular weight having a film forming ability obtained by heating and polymerizing a bifunctional epoxy resin and a halogenated bifunctional phenol in the presence of a catalyst. It is a cured product of a thermosetting epoxy resin composition comprising an epoxy polymer of 100,000 or more, a crosslinking agent, and a polyfunctional epoxy resin.

Such an epoxy polymer having a film-forming ability is a so-called high molecular weight epoxy polymer having a molecular weight of 100,000 or more, and a bifunctional epoxy resin and a halogenated bifunctional phenol are used as a bifunctional epoxy resin. The compounding equivalent ratio of the halogenated bifunctional phenols is set to epoxy group / phenolic hydroxyl group = 1: 0.9 to 1.1, and in the presence of a catalyst, the boiling point is 130 ° C. or higher in an amide-based or ketone-based solvent, the reaction solid It can be obtained by heating and polymerizing at a concentration of 50% by weight or less.

The bifunctional epoxy resin may be any compound as long as it is a compound having two epoxy groups in the molecule, for example, bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin. , Aliphatic chain epoxy resins, etc. The molecular weight of these compounds may be any. Several kinds of these compounds can be used in combination. Further, components other than the bifunctional epoxy resin may be included as impurities.

The halogenated bifunctional phenol may be any compound as long as it has a halogen atom and two phenolic hydroxyl groups, and examples thereof include monocyclic bifunctional phenols such as hydroquinone, resorcinol, catechol and polycyclic. Bifunctional phenol, bisphenol A,
Examples include bisphenol F, naphthalene diols, bisphenols, and halides of these substituted alkyl groups. The molecular weight of these compounds may be any. Several kinds of these compounds can be used in combination, and non-halogenated bifunctional phenols may be used in combination. Further, components other than the bifunctional phenols may be included as impurities.

The catalyst may be any compound having a catalytic ability to promote the etherification reaction of the epoxy group and the phenolic hydroxyl group, and examples thereof include alkali metal compounds, alkaline earth metal compounds and imidazoles.
Organophosphorus compounds, secondary amines, tertiary amines, quaternary ammonium salts and the like. Among them, the alkali metal compound is the most preferable catalyst, and examples of the alkali metal compound include hydroxides of sodium, lithium and potassium,
There are halides, organic acid salts, alcoholates, phenolates, hydrides, borohydrides, amides and the like. These catalysts can be used in combination.

The reaction solvent is preferably an amide solvent or a ketone solvent, and the amide solvent has a boiling point of 13
There is no particular limitation as long as the raw material epoxy resin and phenols are dissolved at 0 ° C. or higher. For example, formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide, N,
Examples include N-dimethylacetamide, N, N, N ′, N′-tetramethylurea, 2-pyrrolidone, N-methyl-2-pyrrolidone, and carbamic acid ester. These solvents can be used in combination. Further, it may be used in combination with other solvents such as a ketone solvent and an ether solvent.

As the polymer synthesis conditions, the compounding equivalent ratio of the bifunctional epoxy resin and the bifunctional phenols or the halogenated bifunctional phenols is epoxy group / phenolic hydroxyl group = 1: 0.9 to 1.1. Is desirable. The amount of the catalyst compounded is not particularly limited, but the amount of the catalyst is generally about 0.0001 to 0.2 mol per mol of the epoxy resin. The polymerization reaction temperature is preferably 60 to 150 ° C. If it is lower than 60 ° C., the high molecular weight reaction is remarkably slow, and if it is higher than 150 ° C., there are many side reactions and the polymer is not linearly increased in molecular weight. The solid content concentration in the polymerization reaction using a solvent may be 50% or less, and more preferably 30% or less. Thus, a so-called high molecular weight epoxy polymer having a film forming ability and having a molecular weight of 100,000 or more can be obtained.

As a cross-linking agent for this high-molecular-weight epoxy polymer, a mask obtained by masking (blocking) isocyanates with another compound having active hydrogen, in which the reactivity of the cross-linking agent can be easily controlled and the storage stability of the varnish can be easily ensured. Isocyanates can be used.

Any isocyanate may be used as long as it has two or more isocyanate groups in the molecule. For example, hexamethylene diisocyanate masked with a masking agent such as phenols, oximes and alcohols. , Diphenylmethane diisocyanate,
Examples thereof include isophorone diisocyanate and tolylene diisocyanate. In particular, isophorone diisocyanate and tolylene diisocyanate masked with phenols are preferable for improving the heat resistance of the cured product. The amount of the cross-linking agent is 0.1 to 1.0 of the isocyanate group based on 1.0 equivalent of the alcoholic hydroxyl group of the high molecular weight epoxy polymer.
It is preferable to make it equivalent.

The polyfunctional epoxy resin may be any compound as long as it is a compound having two or more epoxy groups in the molecule, for example, phenol novolac type epoxy resin, cresol novolac type epoxy resin, resol type epoxy resin. , Bisphenol type epoxy resin and other phenolic glycidyl ether epoxy resin and alicyclic epoxy resin, epoxidized polybutadiene, glycidyl ester type epoxy resin, glycidyl amine type epoxy resin, isocyanurate type epoxy resin, flexible epoxy resin Any epoxy resin may be used, but especially a phenol type epoxy resin,
Alternatively, a mixture of a phenol type epoxy resin and a polyfunctional epoxy resin is preferable for improving heat resistance. The amount of this polyfunctional epoxy resin is based on the high molecular weight epoxy polymer,
It is preferably 20 to 100% by weight.

These polyfunctional epoxy resins may be used alone or in combination of two or more. Further, a curing agent and a curing accelerator for the polyfunctional epoxy resin are used.
Examples of curing agents and curing accelerators for epoxy resins include novolac type phenol resins, dicyandiamide, acid anhydrides, amines, imidazoles, and phosphines. Also, these may be used in combination. Further, a silane coupling agent may be added. The silane coupling agent to be added is preferably epoxy silane, amino silane, urea silane or the like.

The etching solution of the present invention is an amide solvent,
It can be prepared by mixing and mixing an aqueous solution of an alkali metal compound.

The amide solvent which is a constituent of the etching solution of the present invention may be any solvent such as formamide, N-methylformamide, N, N-dimethylformamide, acetamide, N-methylacetamide,
N, N-dimethylacetamide, N, N, N ', N'-
Tetramethylurea, 2-pyrrolidone, N-methyl-2-
Examples include pyrrolidone and carbamic acid ester. Of these, N, N-dimethylformamide, N, N-dimethylacetamide, and N-methyl-2-pyrrolidone are particularly preferable because they have the effect of swelling the epoxy resin cured product and have good solubility of the decomposed product. These solvents can be used in combination. Further, it may be used in combination with other solvents such as a ketone solvent and an ether solvent.

Any ketone-based solvent may be used here, for example, acetone, ethyl ethyl ketone, 2-pentanone, 3-pentanone, 2-hexanone, methyl isobutyl ketone, 2-heptanone, 4-heptanone. , Diisobutyl ketone, cyclohexanone, etc.

Any ether type solvent may be used in combination, for example, dipropyl ether, diisopropyl ether, dibutyl ether, anisole, phenetole, dioxane, tetrahydrofuran,
Examples include ethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol dimethyl ether, and diethylene glycol diethyl ether.

Alkali metal compounds which are constituents of the etching solution of the present invention include lithium, sodium, potassium,
Any alkali metal compound such as rubidium and cesium can be used as long as it is soluble in water.
Metals such as lithium, sodium, potassium, rubidium and cesium, hydrides, hydroxides, borohydrides, amides, fluorides, chlorides, bromides, iodides, borates,
Phosphates, carbonates, sulfates, nitrates, organic acid salts, phenolic salts and the like can be used. Of these, alkali metal hydroxides are preferable, and lithium hydroxide, sodium hydroxide and potassium hydroxide are particularly preferable.

The etching solution of the present invention comprises an amide solvent and an aqueous solution of an alkali metal compound, and the concentration of the alkali metal compound in the aqueous solution of the alkali metal compound may be any concentration, but is from 0.5% by weight to 60% by weight. Is preferred. When the concentration of the alkali metal compound in the aqueous solution of the alkali metal compound is lower than 0.5% by weight, the rate of decomposition of the cured epoxy resin is lowered, which is not preferable, and when it is higher than 60% by weight, the alkali metal compound cannot be completely dissolved in water, which is preferable. Absent.

The etching solution of the present invention is prepared by mixing an amide solvent with an aqueous solution of an alkali metal compound, but phase separation occurs even if it is mixed in any proportion. However, since the phases are separated, the decomposition product of the epoxy resin can be easily dissolved in the amide solvent phase.
Also, the etching solution may be heated to about 90 ° C. before use.

As an etching method, it may be immersed in an etching solution which is phase-separated, but it is preferably immersed in an etching solution which is agitated at high speed and uniformly dispersed. Further, bubbles may be generated or vibration may be applied by ultrasonic waves. A spray or the like may be used without being immersed in the liquid, and further high pressure may be applied.

[0027]

【Example】

Example 1 Thermosetting epoxy adhesive film AS-3000E (manufactured by Hitachi Chemical Co., Ltd.) having a film thickness of 50 μm, which is composed of a brominated high molecular weight epoxy polymer, a phenol resin masked diisocyanate, and a cresol novolac type epoxy resin. (Name) was heated at 170 ° C. for 30 minutes to prepare a cured film of the epoxy resin composition. This cured film was tough and did not break or break when pulled or folded. As an etchant, N, N-
A mixed solution of 80% by weight of dimethylformamide and 20% by weight of an aqueous solution of sodium hydroxide (concentration of sodium hydroxide: 50% by weight) was prepared. When the cured film was immersed in an etching solution at 60 ° C. and shaken lightly, the cured film completely dissolved in 15 minutes.

Example 2 N, N-dimethylformamide 8 was used as an etching solution.
A mixed solution of 0% by weight and 20% by weight of an aqueous solution of potassium hydroxide (potassium hydroxide concentration: 50% by weight) was prepared. The cured film prepared in Example 1 was dipped in an etching solution at 60 ° C. and shaken lightly. The cured film completely dissolved in 15 minutes.

Example 3 N, N-dimethylformamide 8 was used as an etching solution.
A mixed solution of 0 wt% and an aqueous solution of lithium hydroxide (lithium hydroxide concentration: 10 wt%) of 20 wt% was prepared. The cured film prepared in Example 1 was dipped in an etching solution at 60 ° C. and shaken lightly. The cured film completely dissolved in 45 minutes.

Example 4 N, N-dimethylformamide 8 was used as an etching solution.
A mixed solution of 0% by weight and an aqueous solution of sodium hydroxide (sodium hydroxide concentration: 10% by weight) 20% by weight was prepared. The cured film prepared in Example 1 was dipped in an etching solution at 60 ° C. and shaken lightly. The cured film completely dissolved in 25 minutes.

Example 5 N, N-dimethylacetamide 8 was used as an etching solution.
A mixed solution of 0% by weight and an aqueous solution of sodium hydroxide (sodium hydroxide concentration: 20% by weight) 20% by weight was prepared. The cured film prepared in Example 1 was dipped in an etching solution at 60 ° C. and shaken lightly. The cured film completely dissolved in 20 minutes.

Example 6 N-methyl-2-pyrrolidone 80 was used as an etching solution.
A mixed solution containing 20% by weight of an aqueous solution of sodium hydroxide (sodium hydroxide concentration: 20% by weight) was prepared.
The cured film produced in Example 1 was dipped in an etching solution at 60 ° C. and shaken lightly to give a cured film of 25
Completely dissolved in minutes.

Comparative Example 1 The cured film prepared in Example 1 was dipped in N, N-dimethylformamide at 60 ° C. and lightly shaken to give 2
The film remained in its original shape even after 4 hours.

Comparative Example 2 The cured film prepared in Example 1 was used at 20% by weight at 60 ° C.
When immersed in an aqueous solution of sodium hydroxide and shaken lightly, the film remained in its original shape even after 24 hours.

Comparative Example 3 The cured film prepared in Example 1 was immersed in a mixed aqueous solution of 5% by weight sodium hydroxide and 5% by weight potassium permanganate at 60 ° C. and shaken lightly. The surface was only roughened.

[0036]

As described above, according to the present invention, a bifunctional epoxy resin and a halogenated bifunctional phenol are present in the presence of a catalyst by a phase-separated etching solution comprising an amide solvent and an aqueous solution of an alkali metal compound. , A molecular weight of 100 having a film-forming ability when heated and polymerized,
000 or more epoxy polymer, cross-linking agent, cured product of thermosetting epoxy resin composition consisting of polyfunctional epoxy resin can be etched, and for handling concentrated sulfuric acid, chromic acid, alkali permanganate, etc. It is possible to provide a solution that can be etched without the use of sensitive chemicals.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Akashi Nakaso 1500 Ogawa, Shimodate City, Ibaraki Prefecture Hitachi Chemical Co., Ltd. Shimodate Research Center

Claims (4)

[Claims] 1. An epoxy polymer having a molecular weight of 100,000 or more, a cross-linking agent, and a polyfunctional epoxy resin having a film-forming ability, which is obtained by polymerizing a bifunctional epoxy resin and a halogenated bifunctional phenol by heating in the presence of a catalyst. A solution for etching a cured product of a thermosetting epoxy resin composition, which comprises an amide solvent and an aqueous solution of an alkali metal compound. 2. An amide-based solvent is N, N-dimethylformamide, N, N-dimethylacetamide, N-methyl-
It is any one of 2-pyrrolidone, The etching liquid of the epoxy resin hardened material of Claim 1 characterized by the above-mentioned. 3. The etching solution for an epoxy resin cured product according to claim 1, wherein the alkali metal compound is an alkali metal hydroxide. 4. The alkali metal compound is lithium hydroxide,
The etching solution for an epoxy resin cured product according to claim 3, which is either sodium hydroxide or potassium hydroxide.